Here's how it works:
1. Dissolution: Limestone is primarily made of calcium carbonate. When rainwater, which is slightly acidic due to dissolved carbon dioxide, seeps through the ground, it dissolves the limestone. Over time, this process creates cracks and crevices.
2. Enlargement: As the water continues to flow, the cracks expand, forming larger channels and eventually, caves.
3. Groundwater Influence: Groundwater plays a key role in this process:
* Flow: Groundwater flow through the limestone contributes to the dissolution process, widening the cracks.
* Transport: Groundwater carries dissolved minerals, including calcium carbonate, within the cave system.
* Deposits: When groundwater enters the cave and loses pressure, it can precipitate the dissolved minerals, forming speleothems like stalactites, stalagmites, and flowstones. These deposits can cover the cave floor, but they are formed by the groundwater, not the groundwater itself.
So, in summary:
* Groundwater is essential for creating limestone caves through dissolution and enlargement.
* It also contributes to the formation of cave features (speleothems), which can be found on the floor, ceiling, and walls.
* However, groundwater itself doesn't directly "floor" the cave. It's the bedrock, usually limestone, that forms the floor, and the speleothems are deposited on top of it.
